Gears of war 2 matchmaking doesn't work for me. How do I fix it?

I'm from India. I tried to play Gears 2 online but it just won't work. Other games like Halo 3 and Forza 3 work fine. I have tried everything, and even after waiting 15-20 minutes, no players are found.I have tried playing in all game-modes like Execution, Warzone, Annex, KOTH, Guardian. Nothing works. A fix would be welcome. Thanks in advance